fix: 修复PBR纹理属性与材质值混合问题及AO实现

- 将纹理采样从乘法混合改为直接替换
- 添加Material结构的ao字段并在光照计算中正确应用
- 更新demo使用完整的PBR砖墙纹理

examples/assets/normal_map_cornell_box/Bricks092_1K-JPG.mtlx

@@ -0,0 +1,42 @@
+<?xml version="1.0"?>
+<materialx version="1.38" fileprefix="./">
+  <standard_surface xpos="6.159420" name="Bricks092_1K_JPG_StandardSurface" ypos="-1.879310" type="surfaceshader">
+    <input name="specular" value="0" type="float" />
+    <input name="coat" value="1" type="float" />
+    <input name="coat_color" value="1, 1, 1" type="color3" />
+    <input name="base" value="1" type="float" />
+    <input nodename="Bricks092_1K_JPG_Color" name="base_color" type="color3" />
+    <input nodename="normalmap" name="normal" type="vector3" />
+    <input nodename="normalmap" name="coat_normal" type="vector3" />
+    <input nodename="Bricks092_1K_JPG_Roughness" name="specular_roughness" type="float" />
+    <input nodename="Bricks092_1K_JPG_Roughness" name="coat_roughness" type="float" />
+  </standard_surface>
+  <surfacematerial xpos="8.695652" name="Bricks092_1K_JPG" ypos="0.000000" type="material">
+    <input nodename="Bricks092_1K_JPG_StandardSurface" name="surfaceshader" type="surfaceshader" />
+    <input nodename="displacement" name="displacementshader" type="displacementshader" />
+  </surfacematerial>
+  <tiledimage xpos="3.623188" name="Bricks092_1K_JPG_Color" ypos="-3.103448" type="color3">
+    <input name="file" value="Bricks092_1K-JPG_Color.jpg" colorspace="srgb_texture" type="filename" />
+    <input name="uvtiling" value="1.0, 1.0" type="vector2" />
+  </tiledimage>
+  <tiledimage xpos="3.623188" name="Bricks092_1K_JPG_Displacement" ypos="5.163793" type="float">
+    <input name="file" value="Bricks092_1K-JPG_Displacement.jpg" type="filename" />
+    <input name="uvtiling" value="1.0, 1.0" type="vector2" />
+  </tiledimage>
+  <displacement xpos="6.159420" name="displacement" ypos="1.879310" type="displacementshader">
+    <input nodename="Bricks092_1K_JPG_Displacement" name="displacement" type="float" />
+    <input name="scale" value="1.0" type="float" />
+  </displacement>
+  <tiledimage xpos="1.086957" name="Bricks092_1K_JPG_NormalGL" ypos="0.879310" type="vector3">
+    <input name="file" value="Bricks092_1K-JPG_NormalGL.jpg" type="filename" />
+    <input name="uvtiling" value="1.0, 1.0" type="vector2" />
+  </tiledimage>
+  <normalmap xpos="3.623188" name="normalmap" ypos="3.586207" type="vector3">
+    <input nodename="Bricks092_1K_JPG_NormalGL" name="in" type="vector3" />
+    <input name="scale" value="1.0" type="float" />
+  </normalmap>
+  <tiledimage xpos="3.623188" name="Bricks092_1K_JPG_Roughness" ypos="-0.413793" type="float">
+    <input name="file" value="Bricks092_1K-JPG_Roughness.jpg" type="filename" />
+    <input name="uvtiling" value="1.0, 1.0" type="vector2" />
+  </tiledimage>
+</materialx>

examples/normal_map_cornell_box.cpp

@@ -1,13 +1,6 @@
-#include <core/renderer.h>
-#include <scene/scene.h>
-#include <scene/camera.h>
-#include <scene/mesh.h>
-#include <scene/material.h>
-#include <scene/light.h>
-#include <resource/texture.h>
-#include <utils/logger.h>
 #include <glad/glad.h>
 #include <GLFW/glfw3.h>
+#include <core/renderer.h>
 #include <glm/glm.hpp>
 #include <glm/gtc/matrix_transform.hpp>
 #include <glm/gtc/quaternion.hpp>
@@ -223,31 +216,48 @@ void setup_cornell_box() {
 	metal_material->set_type(MaterialType::METAL);
 	uint metal_id = g_scene->add_material(metal_material);
 
-	// 5: Textured material with normal map (for short box)
+	// 5: Textured material with PBR textures (for short box)
 	auto textured_material = std::make_shared<Material>();
-	textured_material->set_albedo(Vec3(1.0f, 1.0f, 1.0f));
+	textured_material->set_albedo(Vec3(1.0f, 0.0f, 1.0f));
-	textured_material->set_metallic(1.0f);
+	metal_material->set_metallic(1.0f);
-	textured_material->set_roughness(1.0f);
+	metal_material->set_roughness(0.0f);
-	// textured_material->set_type(MaterialType::DIFFUSE);
+	// textured_material->set_metallic(0.0f);
-	textured_material->set_type(MaterialType::METAL);
+	// textured_material->set_roughness(0.0f);
+	textured_material->set_type(MaterialType::DIFFUSE);
 
-	// Load textures
+	// Load PBR textures
-	// auto albedo_tex = std::make_shared<are::Texture>();
+	auto albedo_tex = std::make_shared<are::Texture>();
-	// if (albedo_tex->load_from_file("examples/assets/normal_map_cornell_box/albedo.png")) {
+	if (albedo_tex->load_from_file("examples/assets/normal_map_cornell_box/Bricks092_1K-JPG_Color.jpg")) {
-	// 	textured_material->set_albedo_texture(albedo_tex);
+		textured_material->set_albedo_texture(albedo_tex);
-	// 	ARE_LOG_INFO("Loaded albedo texture");
+		ARE_LOG_INFO("Loaded albedo texture");
-	// } else {
+	} else {
-	// 	ARE_LOG_WARN("Failed to load albedo texture");
+		ARE_LOG_WARN("Failed to load albedo texture");
-	// }
+	}
 
 	auto normal_tex = std::make_shared<are::Texture>();
-	if (normal_tex->load_from_file("examples/assets/normal_map_cornell_box/normal.png")) {
+	if (normal_tex->load_from_file("examples/assets/normal_map_cornell_box/Bricks092_1K-JPG_NormalGL.jpg")) {
 		textured_material->set_normal_texture(normal_tex);
 		ARE_LOG_INFO("Loaded normal texture");
 	} else {
 		ARE_LOG_WARN("Failed to load normal texture");
 	}
 
+	auto roughness_tex = std::make_shared<are::Texture>();
+	if (roughness_tex->load_from_file("examples/assets/normal_map_cornell_box/Bricks092_1K-JPG_Roughness.jpg")) {
+		textured_material->set_roughness_texture(roughness_tex);
+		ARE_LOG_INFO("Loaded roughness texture");
+	} else {
+		ARE_LOG_WARN("Failed to load roughness texture");
+	}
+
+	auto ao_tex = std::make_shared<are::Texture>();
+	if (ao_tex->load_from_file("examples/assets/normal_map_cornell_box/Bricks092_1K-JPG_AmbientOcclusion.jpg")) {
+		textured_material->set_ao_texture(ao_tex);
+		ARE_LOG_INFO("Loaded AO texture");
+	} else {
+		ARE_LOG_WARN("Failed to load AO texture");
+	}
+
 	uint textured_id = g_scene->add_material(textured_material);
 
 	// 6: Glass/Dielectric (refraction)
@@ -298,7 +308,7 @@ void setup_cornell_box() {
 		Vec3(room_size, -room_size, -room_size),
 		Vec3(0.0f, 0.0f, 1.0f),
 		metal_id);
-		// white_id);
+	// white_id);
 	back_wall->upload_to_gpu();
 	g_scene->add_mesh(back_wall);
 

shaders/raytracing.comp

@@ -43,8 +43,8 @@ struct Material {
     float roughness;
     int type;
     float ior;
+    float ao;        // ambient occlusion
     float padding1;
-    float padding2;
     uint texture_handles[6];
 };
 
@@ -458,9 +458,9 @@ vec3 apply_normal_map(vec3 normal, vec2 texcoord, vec3 tangent, uint normal_hand
 void apply_material_textures(inout Material mat, inout vec3 normal, vec2 texcoord, vec3 tangent) {
     if (!u_enable_textures) return;
     
-    // Albedo texture
+    // Albedo texture (replace)
     if (mat.texture_handles[0] != 0) {
-        mat.albedo *= sample_texture_array(0, int(mat.texture_handles[0]), texcoord).rgb;
+        mat.albedo = sample_texture_array(0, int(mat.texture_handles[0]), texcoord).rgb;
     }
     
     // Normal map
@@ -468,25 +468,24 @@ void apply_material_textures(inout Material mat, inout vec3 normal, vec2 texcoor
         normal = apply_normal_map(normal, texcoord, tangent, mat.texture_handles[1]);
     }
     
-    // Metallic texture
+    // Metallic texture (replace)
     if (mat.texture_handles[2] != 0) {
-        mat.metallic *= sample_texture_array(2, int(mat.texture_handles[2]), texcoord).r;
+        mat.metallic = sample_texture_array(2, int(mat.texture_handles[2]), texcoord).r;
     }
     
-    // Roughness texture
+    // Roughness texture (replace)
     if (mat.texture_handles[3] != 0) {
-        mat.roughness *= sample_texture_array(3, int(mat.texture_handles[3]), texcoord).r;
+        mat.roughness = sample_texture_array(3, int(mat.texture_handles[3]), texcoord).r;
     }
     
-    // AO texture (multiply)
+    // AO texture (store in material, apply during lighting)
     if (mat.texture_handles[4] != 0) {
-        float ao = sample_texture_array(4, int(mat.texture_handles[4]), texcoord).r;
+        mat.ao = sample_texture_array(4, int(mat.texture_handles[4]), texcoord).r;
-        mat.albedo *= ao;
     }
     
-    // Emission texture (add)
+    // Emission texture (replace)
     if (mat.texture_handles[5] != 0) {
-        mat.emission += sample_texture_array(5, int(mat.texture_handles[5]), texcoord).rgb;
+        mat.emission = sample_texture_array(5, int(mat.texture_handles[5]), texcoord).rgb;
     }
 }
 
@@ -623,7 +622,8 @@ vec3 eval_direct_lighting(inout HitInfo hit, Material mat, inout uint seed) {
 
     float pdf_light = 1.0 / float(u_light_count);
     vec3 brdf = mat.albedo * INV_PI;
-    return brdf * radiance * n_dot_l / max(pdf_light, EPSILON);
+    // Apply AO to the final lighting
+    return brdf * radiance * n_dot_l * mat.ao / max(pdf_light, EPSILON);
 }
 
 // ============================================================================
@@ -641,6 +641,7 @@ Material fetch_material(uint material_id) {
     m.roughness = 0.5;
     m.type = MATERIAL_DIFFUSE;
     m.ior = 1.5;
+    m.ao = 1.0;  // default: no AO
     return m;
 }
 

src/core/raytracer.cpp

@@ -306,8 +306,8 @@ void RayTracer::upload_scene_data_(const Scene &scene) {
 			float roughness;
 			int type;
 			float ior;
+			float ao;
 			float padding1;
-			float padding2;
 			uint texture_handles[6];
 		};
 
@@ -322,6 +322,7 @@ void RayTracer::upload_scene_data_(const Scene &scene) {
 			data.roughness = mat->get_roughness();
 			data.type = static_cast<int>(mat->get_type());
 			data.ior = mat->get_ior();
+			data.ao = 1.0f; // default: no AO
 
 			// Texture array indices (0 = no texture, 1+ = index into array)
 			data.texture_handles[0] = mat->get_texture_index(TextureSlot::ALBEDO);